Electricity and electrically powered systems are becoming ubiquitous and it is becoming increasingly desirable to find sources of power. For example, various systems may convert various petrochemical compounds, e.g. carbonaceous materials such as coal and petcoke, into electrical energy. Further, such petrochemical compounds are used to create various other materials such as steam that are used to drive steam powered turbines.
The gasification of carbonaceous materials such as coal and petcoke into synthesis gas (syngas), e.g. mixtures of hydrogen and carbon monoxide, is a well-known industrial process used in the petrochemical and gas power turbine industries. Over the last 20 years, entrained flow coal gasifiers have become the leading process in the production of synthesis gas. However, these entrained flow gasifiers fail to make use of rapid mix injector technology. The failure to use such technologies causes gasifier volumes and gasifier capital costs to be much higher than necessary. Rapid mix injector technology is expected to reduce these entrained flow gasifier volumes by about one order of magnitude, i.e. by a factor of 10. Getting the overall capital cost of these coal gasifiers down by significantly reducing gasifier volumes is very desirable.
Since 1975, Rocketdyne has designed and tested a number of rapid mix injectors for coal gasification. Most of these designs and test programs were conducted under U.S. Department of Energy contracts between 1975 and 1985. The primary workhorse injector used on these DOE programs was the multi-element pentad. Each pentad (4-on-1) element used four high velocity gas streams which impinged onto a central coal slurry stream. The four gas stream orifices were placed 90 degrees apart from each other on a circle surrounding the central coal slurry orifice. The impingement angle between a gas jet and the central coal slurry stream was typically 30 degrees. Each pentad element was sized to flow approximately 4-tons/hr (i.e., 100 tons/day) of dry coal so that a commercial gasifier operating at a 3,600 ton/day capacity would use approximately 36 pentad elements.
Generally, known rapid mix injectors for coal gasification that impinge oxygen gas or a mixture of oxygen and steam on a slurry stream are effective, but degrade quickly because of the high coal/oxygen combustion temperatures that occur very close to the injector face under local oxidation environmental conditions. These combustion temperatures can exceed 5,000° F. in many instances. Additionally, such known rapid mix injectors are susceptible to plugging within the coal slurry stream.